The present application relates to optical sensing systems for detecting chemicals and biological agents.
Optical sensing systems have been used for detecting chemicals and biological agents. In such detection techniques, chemical molecules to be detected are adsorbed on the surfaces of an optical sensor. An incident light beam such as a laser beam illuminates the sensing surfaces adsorbed with the molecules. The incident light beam is scattered by the surfaces. The scattered light is collected and used to determine the identity of the chemical.
A challenge to the optical sensing technique is that the intensity of the scattered light is often too weak for identifying low concentration level of chemicals, which limits the application of the optical sensing techniques for detecting chemicals. For example, it is difficult to reliably detect trace level of chemicals in the field using optical sensing techniques. Trace chemical detection usually needs to be carried out in a wet laboratory.